Two major types of services, that is, a sensor (sensor) service and an offloading (offloading) service, that are completely different exist in a current wireless local area network standard (for example, 802.11ah), and their characteristics and network requirements are greatly different. The sensor (sensor) service may also be referred to as a sensor type service. Characteristics of the sensor service are that a duty cycle (duty cycle) is long, a transmitted packet is short, and the sensor service is mainly an uplink service. Characteristics of the offloading service are that a duty cycle is short, many burst services exist, a transmitted packet is long, and the offloading service is mainly a downlink service. These two types of services are different; in addition, one of the two types of services, for example, the sensor service, may be further subcategorized into a plurality of types. For example, sensors of a plurality of applications, such as, an electricity meter, a water meter, and a fire alarm, may exist in a network, and different types of sensor services obviously have different characteristics and requirements. It is necessary to consider discriminately providing different types of services for different types of services in the network, so as to meet requirements of various types of services. For example, according to service type differences, an access point (Access Point, AP) may determine different maximum idle periods (Max Idle Period), provide different frame header compression methods, determine different DTIM intervals, allocate AIDs, and the like.
However, currently, a service type is mostly indicated in a signal SIG field, where one bit in the SIG field is used to indicate a service type to which currently transmitted data belongs, so as to indicate whether the service is a sensor service or an offloading service, but subcategorization cannot be further performed. For example, the Sensor service may be categorized into an electricity meter service, a water meter service, a medical sensor service, and the like according to service types, or may be subcategorized according to lengths of duty cycles. The offloading service may be categorized into a delay-sensitive service, such as a video or an audio, and a delay-insensitive service, such as file download.